T1=2^8 - (1210 ^6100*10 ^-6)/12=156=9CH
TH1=9CH
TL1=9CH
ORG 0000H
LJMP MAIN
ORG 001BH
CPL P1.0
MAIN: MOV TMOD, #20H
MOV TH1, #9CH
MOV TL1, #9CH
SETB ET1
CLR P1.0
SETB EA
SETB TR1
SJMP $
END

T1=2^8 - (1210 ^6100*10 ^-6)/12=156=9CH
TH1=9CH
TL1=9CH
ORG 0000H
LJMP MAIN
ORG 001BH
CPL P1.0
MAIN: MOV TMOD, #20H
MOV TH1, #9CH
MOV TL1, #9CH
SETB ET1
CLR P1.0
SETB EA
SETB TR1
SJMP $
END